1. Field of the Invention
The present invention relates to a tenter apparatus, and particularly to a tenter apparatus for producing a sheet-form material of a film and so forth, in which an orientation axis inclines relative to a lateral side by an angle of 10xc2x0 or more and 80xc2x0 or less.
2. Description of the Related Art
Conventionally, when a tenter apparatus produces a sheet-form material of a film and so forth in which an orientation axis is declined, for example, by 45xc2x0 relative to a lateral side, orienting is merely performed at a routinely-fixed orienting magnification which is theoretically calculated in advance, such as described in Japanese Patent Publication Nos. 50-83482 and 2-113920.
Since orienting can not be performed at any orienting magnification except the fixed orienting magnification, it is difficult to obtain a sheet-form material of a film and so forth inclining at 45xc2x0 or thereabout, for example, which is aimed at an optional orienting magnification. Thus, there arises a problem in that a yield rate for cut products is not improved. Further, since oblique films having a fixed orienting magnification and a fixed width are merely produced, there arises a problem in that general-purpose properties are poor.
In view of the foregoing, it is a primary object of the present invention to provide a tenter apparatus in which a sheet-form material of a film and so forth having an orientation axis declined relative to a lateral side by an angle of 10xc2x0 or more and 80xc2x0 or less is produced at an optional orienting magnification and in an optional width.
In order to achieve the above and other objects, in the tenter apparatus according to the present invention, preheating is performed while side edges of a sheet-form material are held and moved by film grips running along a left tenter rail and a right tenter rail at a same speed. After preheating, orientation is carried out in a width direction. The right and left tenter rails are constituted of an entrance rail portion, an exit rail portion, and a rail connecting portion. These rail portions and the rail connecting portions are provided with positioning members which are used for changing a width and are independent regarding the right and left sides. In accordance with an orienting magnification optionally set, the respective positioning members are controlled to adjust a distance between right and left rail bending portions. In virtue of this, under the optional orienting magnification, an orientation axis is adapted to incline at an angle of 45xc2x0xc2x15xc2x0 relative to a side edge of a film. Incidentally, it is preferable that the positioning member is constituted of a lead screw for changing the width, a positioning motor for rotating the lead screw, and a female screw region meshing with the lead screw and attached to each of the rail portions and the rail connecting portions. It is preferable that the positioning motor is controlled on the basis of an operation expression programmed in advance.
According to the present invention, it is possible to improve a degree of freely moving the respective rails. The sheet-form material of a film and so forth, in which the orientation axis is declined relative to the side edge by an angle of 10xc2x0 or more and 80xc2x0 or less, may be produced at any orienting magnification so as to have any width in a loss-reducing state. Further, various changes of rail patterns may be easily performed in a short time.